Re: Standard 8 '49 - oil pressure

Posted by Dave Kenney On 2008/2/27 20:33:51

Tim, I have looked in the reprint copy of the 1946-50 Packard manual from the PAC, my 1954 Packard Service manual and my trusty Motor's Manual . While there is a mention of using a direct reading guage in place of the sender unit there is no mention of the sender having a "correction factor" or that the readings on the direct reading gauge should show any different readings than the dash gauge. Would you possibly be able to cite where you obtained your information since I do have a high quality direct reading gauge connected permanently to the engine oil pressure sender orifice with a "T" fitting. The two gauges do not read the same with the direct gauge generally reading about 5lbs. lower when oil is hot. I would like to know what correction factors I would apply to ensure I am getting an accurate reading. The engine in my car is the 356CID model which by the manual should have a "normal driving speed"" oil pressure of 50psi. It normally runs at about 40-45 on the dash gauge at 30mph or higher.
I do agree with your advice about not being concerned about lower than "normal" oil pressure if engine is not making expensive noises. Unless the rod or main bearings are clattering it doesn't necessarily make good economic sense to rebuild an engine for the sake of a few pounds of oil pressure if all that is planned are trips to local shows or cruise nights.